The IFN-induced MLV restriction activity in OMK cells is independent of TRIMCyp. A. OMK cells were transfected with a siRNA targeting luciferase (Luc) or TRIMCyp (as well as CypA), as indicated, and stimulated 24 h later with 1000 U/ml of IFN-β for 8 h. Total RNA was extracted and the levels of TRIMCyp mRNA were determined by quantitative RT-PCR and normalized to GAPDH. The mean ± SD of duplicates is shown. B. OMK cells were transfected with anti-Luc (diamonds) or anti-TRIMCyp (triangles) siRNA and transduced 48 h later with increasing doses of HIV-1. The percentage of GFP-positive cells was determined by FACS 48 h post-transduction. C. Same experiment as in panel B, except that cells were challenged with HIV-1, N-MLV, B-MLV or NB-MLV (at a MOI of 5), following siRNA and IFN-β treatments. The percentage of GFP-positive cells was determined by FACS 48 h post-transduction. Data are from a typical experiment representative of three independent experiments.